Typical electric motors use brush boxes to contain the brush and restrict its movement. Very tight tolerances on both the brush dimensions and the box dimensions are required to minimize brush displacement. The size of the gap between the brush and the box is directly proportional to the sound quality and sound level of the brush system.
Thus, there is a need to provide a brush tube structure that eliminates the conventional gap between the brush and the box, while permitting the brush to travel and wear over the life of the motor.